challenge = $challenge; $this->appId = $appId; } public function version() { return $this->version; } public function challenge() { return $this->challenge; } public function appId() { return $this->appId; } public function jsonSerialize() { return [ 'version' => $this->version, 'challenge' => $this->challenge, 'appId' => $this->appId, ]; } }